Determination of neutron capture reaction rate with new method for nucleosynthesis at neutron star merger

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01114
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Institute of Physical and Chemical Research (2022-2023); Rikkyo University (2021)
• Principal Investigator: Togano Yasuhiro 国立研究開発法人理化学研究所, 仁科加速器科学研究センター, 協力研究員 (20517643)
• Co-Investigator(Kenkyū-buntansha): 中村 隆司 東京工業大学, 理学院, 教授 (50272456)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 実験核物理 / 中性子過剰核 / 中性子捕獲反応 / 元素合成 / 不安定核

Outline of Final Research Achievements

This study aimed at determining neutron capture reaction rates on many neutron-rich nuclei, which impact nucleosynthesis process in neutron-star mergers, using a new indirect method. A new detector to measure energies of protons and gamma rays are developed. The prototype of the new detector was tested as QST-HIMAC, and the full setup of the new detector was utilized to investigate neutron-rich nuclei at RIBF. In addition, three days of beam time was approved by RIBF for evaluating the new method.

Free Research Field

実験核物理

Academic Significance and Societal Importance of the Research Achievements

鉄より重い重元素の起源は自然科学の大きな問題の1つである。中性子星合体が重元素の起源天体の1つであるが、その元素合成過程の詳細は原子核反応の不定性が原因の1つとなり未だ不明である。本研究の新手法を用いれば原子核反応の1つである中性子捕獲反応の不定性を小さくすることができ、中性子星合体における重元素合成過程の詳細な議論が可能となる。